"The tampering, which affected fewer than 1 percent of PIN pads in Barnes & Noble stores, was a sophisticated criminal effort to steal credit card information, debit card information, and debit card PIN numbers from customers who swiped their cards through PIN pads when they made purchases. This situation involved only purchases in which a customer swiped a credit or debit card in a store using one of the compromised PIN pads."

The retailer advises customers who used debit cards in the stores to:

-- "Change the PIN numbers on their debit cards."

-- "Review their accounts for unauthorized transactions."

-- "Notify their banks immediately if they discover any unauthorized purchases or withdrawals."

And it advises credit card users to:

-- "Review their statements for any unauthorized transactions."

-- "Notify their card-issuing banks if they discover any unauthorized purchases or cash advances."

Where are the 63 stores? Here's the list (click on the title to pop up a larger version).